When Dr. Lauren Boswell (Hilarie Burton) came to the Grey Sloan Memorial Hospital, she pretty much immediately set her sights on Arizona, openly flirting with the married doctor (and mother), even in front of her wife, Callie! Even though Arizona (sort of) rebuffed her advances last week, Arizona gave in this week, kissing Lauren in an on-call room when the power went out and then locking the door for, well, you know. TVGuide.com turned to Capshaw to get her reaction to the big development and find out what's next for Calzona:

How surprised were you when you learned the story was going in this direction? Jessica Capshaw: It was one of those moments where I was completely shocked. Completely, completely totally blown away. But there was something about this, when Shonda and I were talking, that seemed like it rang true. If you look at where Arizona has been this season, for me to have played the first four episodes of the show where I don't know that I had a stich of makeup on, to the end of the season with the hair and makeup and being the object of someone's affection. Just Arizona — forget about her being part of a couple — she's gone so far. It's been so profound. This change in her and what has happened to her, she had almost been reborn in this strange way as this new, but the same, person.

When I found out the story was going in this direction, I thought it was a great dilemma for her to have to deal with. It seems like that would happen. Shonda has said before that the writers, herself and myself have done so much research into the kind of things that happen to people who go through experiences like this where a lot of times they find themselves six months or a year post doing things that they would never have done before, and somehow being driven by this other feeling or this differentness that now lives in them. It's really interesting. I know it's devastating! It is. Obviously we've shot everything, and there's a moment Shonda has talked about that we filmed this scene that's really chilling. It's so deep and it's just very provocative.

Can you talk about Arizona's mindset when Lauren is flirting with her? Is she happy someone is attracted to her? Is she desperate to feel something new or alive? Capshaw: I think Arizona was really surprised and wondering why she was initially talking to her. I think she didn't know what to do with the feelings, so she was Arizona about it. She responded in kind, but always kept things clean. I have always felt like Arizona's moral compass is pretty true, and it seems like that was going on last week when Lauren says, "Look at your beautiful eyes." Arizona felt like she needed to come clean because there is a little bit of a pull and when that happens to anyone, it becomes clear that you have to lay down what your boundaries are. That's why she turned around and said, "Listen, I'm married. You met her and she's a great person."

I think it's really interesting because the last thing she says is, "Also, I have one leg." When we went to go shoot this scene, it was so hard to get that line out in a way that felt natural. It was stuck on the end of this big, long monologue, but it was the essence of why, on some level, she was so surprised why someone was so attracted to her and she was feeling the way that she used to feel in terms of people being attracted to her. She felt like if she told Lauren she had one leg, then maybe this would probably all stop. As soon as Lauren found out she only had one leg, for sure she wasn't going to be attracted to her anymore. Again, that's the interesting part. Arizona is this new person who's starting to feel whole again, minus the loss, and that's going to bring up different feelings and it's a situation where she's going to be tested.

What does that conversation with Callie look like in the finale? I can imagine being stuck in the close quarters of the hospital because of the storm will make everything more heightened. Capshaw: Yes, I think that it will. It's devastating. This is what the viewers are going to really probably feel the most. It's really scary to feel this way. My goodness, Callie and Arizona have been through Africa, they've been through the baby, they've been through a car crash, they've been through a plane crash. They've been through so much and it just started to seem like it was getting back to normal again and then why now? Why now is Arizona falling apart and making different choices? That's what makes Grey's Anatomy Grey's Anatomy.

I kept thinking back about before I was on the show and how much I was a fan myself. For five years, I watched it and I loved it and sometimes I hated it because there was all this bed-hopping. You really rooted for this couple and something would change and there would be someone new and you'd hate that person. Then, all of a sudden, you saw why that person was interesting and what that person brings to the table. Then you were very grateful for the challenge and the spiciness because you went, "Oh right, this isn't real life. I'm watching a drama and it's meant to make me feel things, question things and it's meant to make me want to throw a tomato at the TV as much as it meant to make me feel like I wished that one of those characters was my best friend." That's what great TV is. Anyone who is writing a show and any actor who is on a show is chasing that ability to make viewers question and think and feel in a way that is way more exciting than what might be happening in your real life. Unfortunately, obviously, some of that can be really also heartbreaking. That's why I have said from the very beginning of my entire experience at Grey's that you have to lean into it. If you lean away and you try to make it not so, it'll make you crazy. You have to trust that you're on a rollercoaster and what goes up must come down and maybe it'll zig-zag around and maybe it'll take a different loop than you thought it would, but you're going to be there to see what happens.

Are there more underlying problems in this relationship besides the fallout from the plane crash? Capshaw: None that have been specifically addressed between me and any of the writers, although, listen, I could certainly think of things from when Arizona gets back from Africa to now. I think you can follow the breadcrumbs. There's a lot that's happened to them. There was a baby and the ownership of the baby — it wasn't infidelity because they weren't together, but on some level, weren't they? I definitely think that everything that's happened to them has led to this point. The biggest thing is that Arizona is being confronted with the idea that she can be seen as something whole, something new and exciting and attractive.

Do you think there's hope for Callie and Arizona? Capshaw: I don't know. We all know just being on the show, even if there's a concrete answer one way or the other, it could always change. I don't know how you come back from this. It depends on how characters rebound from certain things: whether or not you can ever truly come back from infidelity, whether or not that trust is broken, whether or not you can reclaim it. There's so many different questions.

Do you feel like part of Arizona thinks what she did is forgivable? Capshaw: I don't think that Arizona wanted to do anything wrong. It was a crime of passion. If she had been thinking, she would never have done anything. She had a moment where she didn't and that was the only way I could play it. I could never have played it being purposeful because of course she knows that she's a wife and she's a mother and how could she ever do this? I think there's not much thought in it and that's probably what she will cling to — is not having felt like she was in control or knowing what she was doing. Then beyond that, I don't know. I think she'll take responsibility because that's the kind of character that she is. It was never going to be Arizona cheating and then sneaking around, and that's very clear. That's not who she is.

One of my favorite scenes in Grey's history was when Callie was going to fight Izzie (Katherine Heigl) in the commissary because of George (T.R. Knight). Could we see Callie want to fight Lauren, or is this more just devastation? Capshaw: It's devastation. It's so heartbreaking. This is their defining moment. I think every character that's a regular on the show right now has, on the show, been with at least two or more people except for Arizona. Arizona is the pristine woman who met her lady, signed up and it's been what it is. Besides the devastating things that have happened, they've been the happy couple. Shonda and I talked about this a lot, which is that you can't have the relationship just live this happy fairytale. It's not fair. You have to give them the same obstacles that you give other couples. It's in the name of this being this provocative drama when you're meant to feel things, root for things, be upset and get over it, and then figure out why. Maybe there's something understandable about what she has done on some level. That's what's meant to be probably the most heartbreaking part. I think that some people will just be Team Callie or Team Arizona. But I do think that the people who really think about what's happened, you'll be able to see how devastating and how heartbreaking it is for both of them. There's a real reason for both of their circumstances.

What do you want to say to Callie and Arizona fans who are undoubtedly devastated after this? Capshaw: I know! I know! Listen, it's really important to remember — and I so understand the investment in TV characters because they're in your home every week — but this is a challenge and it's part of a story. Nothing is written in stone and I don't know that anyone knows exactly what's going to happen, but I can almost guarantee that whatever happens is going to still be, as Grey's Anatomy is, thrilling, exciting and heartbreaking.